Author Topic: Shake at 75-80 mph  (Read 388 times)

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Offline vetteandharley

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Shake at 75-80 mph
« on: August 12, 2019, 06:25:58 AM »
  Purchased a used 2017 Road Glide Special in late February of this year with 13,000 miles on it.  Bike rides smooth as glass up to 75-.80 mph and then the vibration starts.  At 18,500 miles I changed both front and rear tires and used dyna beads.
The rear wheel had 30 grams of weights which I removed and compensated for with extra beads. Vibration is actually a little worse now than before the new tires.  What should I be looking for?  TIA

Offline screem

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Re: Shake at 75-80 mph
« Reply #1 on: August 12, 2019, 06:44:02 AM »
Check neck bearings by doing the fall away test.. check the swing of the front end, and while your at it, probably change fork fluid too

Offline Hossamania

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Re: Shake at 75-80 mph
« Reply #2 on: August 12, 2019, 07:34:22 AM »
Check for warped rotors. Put the tires on a balancing machine and check them. Check for a bent rim.
« Last Edit: August 12, 2019, 07:49:53 AM by Hossamania »
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Offline guydoc77

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Re: Shake at 75-80 mph
« Reply #3 on: August 12, 2019, 08:06:23 AM »
My '15 has done this since new.
I think it is shuddering from the fairing, at least on mine.
I experimented with opening all or one or two of the vents and it definitely makes a difference.

Offline Boe Cole

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Re: Shake at 75-80 mph
« Reply #4 on: August 12, 2019, 09:50:48 AM »
Although my RGU is a 2011, its rock solid to 100+.  I don't think the problem is in the fairing - would be looking at bent rims, tire balance and loose neck bearings.  The RG's are very sensitive to loose or overly tight neck bearings.  Loose causes a serious wobble in the 30-40 mph range on decel.  Have not experienced trouble with overly tight bearings but have heard somewhere that tight causes high speed handling issues.
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Offline guydoc77

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Re: Shake at 75-80 mph
« Reply #5 on: August 12, 2019, 10:14:52 AM »
My '08 is the same.
The '15 is a totally different bike than either the '08 or '11.
And I don't think it is the fairing that is actually shaking per se.
But the wind going around it causes the "shake".
The shake is a minor annoyance I should point out.
And it is present less or more depending on wind speed and direction and, as stated, on which and how many vent(s) I have open.
The bike handles too well in curves to be a steering head issue IMO.

I would add that yesterday, on the way home, we were running triple digits at times in order to beat severe weather to the house. The last leg going north we had a tail wind and there was no shaking.
The shaking always seems to occur with a diagonal headwind/crosswind.

Offline Moparnut72

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Re: Shake at 75-80 mph
« Reply #6 on: August 12, 2019, 10:24:52 AM »
I once bought a Sporty without a road test, on line sale at a great price. It turned out that it had a terrible slow speed handling problem. It was fine over 30 mph.  I put it on the lift to check the fall away. It was tight as hell. So I set it up as per the manual. Slow speed handling was now good but at highway speeds it had an ocillation back and forth. It turned out there was small dent in the wheel that wasn't visible to the naked eye. A new wheel made it all good. The used bike dealer had tightened the neck bearings to cover up the highways speed wobble. Things you might look for.
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Offline 1workinman

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Re: Shake at 75-80 mph
« Reply #7 on: August 12, 2019, 07:37:51 PM »
My Street Glide has never done that even way over the limit two up loaded .  Now my 13 Road Glide would do that at 85 or so . Steve replace the front end and now its rock steady . Took it for a spin two up and I did not realize the how fast it was going as the odometer was broke  , I thought ,for a second . It took it a bit to start moving down or slowing down . Not a bobble or shake one , gone I had no idea how fast it was going but a bit over the speed limit .Not sure if it was the neck bearings or the 21 inch wheel or what as the damn shake is gone . Very happy as 143 will get to 85 even two very quickly lol

Offline smoserx1

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Re: Shake at 75-80 mph
« Reply #8 on: August 13, 2019, 05:58:38 AM »
I doubt it is warped rotors.  That should be felt as a brake pulsation that is always there, regardless of speed.  Increasing the speed would simply change the frequency.  Pretty much ditto for a bent rim, plus if you put your bike on a lift you should be able to rotate the wheels and see that.  Any bend is very obvious to the eye.  And new tires did not solve the problem.  you might want to check if your rims themselves are out of balance.  All it takes is a static balancer or your bike's axle and two even height surfaces (like 2 jack stands).  Any weight attached to the rims needs removing.  If it always comes to rest with the same spot at the bottom (and this is not the valve stem) your rims themselves are not balanced.  I know for a fact neither of mine are, and the rear is significantly off, and it isn't bent, the rotor is fine and so are the bearings.  It has never caused me any problem but then I don't go over 80.  I am a chicken.  I have also heard if your rims aren't balanced you might try balancing just the rims without tires (just tape on the weights and record what it takes and mark the location on the rim).  Or you might try installing the tire with the balance mark opposite this spot instead of the valve stem.  Most shops with machine balancers don't do this but you can at least talk to them about it.
« Last Edit: August 13, 2019, 06:15:04 AM by smoserx1 »

Offline vetteandharley

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Re: Shake at 75-80 mph
« Reply #9 on: August 13, 2019, 06:33:53 AM »
Thanks to everyone for the suggestions. I have an appointment this morning for the clutch recall and if they have time I'll have them perform the fall away test and tighten the neck bearings if needed. I don't drive interstates often but here in the midwest the speed limits are 80-85 so would like to eliminate the problem.  Thanks again.

Offline Y2KRKNG

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Re: Shake at 75-80 mph
« Reply #10 on: August 13, 2019, 11:36:48 AM »
The wheel bearings are  :turd: on the newer bikes. Need to check them too
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Offline screem

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Re: Shake at 75-80 mph
« Reply #11 on: August 13, 2019, 12:51:18 PM »
Thanks to everyone for the suggestions. I have an appointment this morning for the clutch recall and if they have time I'll have them perform the fall away test and tighten the neck bearings if needed. I don't drive interstates often but here in the midwest the speed limits are 80-85 so would like to eliminate the problem.  Thanks again.

Please let us know what it turns out to be